Dystonia represents a clinical syndrome characterized by involuntary sustained muscle contraction often resulting in twisting, repetitive movements and abnormal postures. Dystonia can be both primary (idiopathic) or symptomatic. Symptomatic or secondary dystonias are caused by varied structural or metabolic disturbances of the nervous system which may result from an underlying disease or drug treatment. Idiopathic dystonias are composed of a spectrum of disorders in which dystonia is the predominant clinical feature. X-linked dystonia parkinsonism is a recessively inherited, severe, adult-onset movement disorder. It is characterized by dystonia, predominantly focal at presentation, progressing to a generalized form with co-incidental parkinsonism in about 50% of cases. XDP is believed to originate from a common ancestor in the Philippine island of Panay. Linkage and allelic association studies have mapped the gene defect causing this disorder to a small interval in Xq13.1. In collaboration with Drs Virgiglio Evidente Dennis Dickson (mayo Clinic Scottsdale and Jacksonville respectively) we have further characterized the clinical and pathological aspects of this disorder in an attempt to better understand the disease process. This work is not only aimed at gaining insight into the pathogenesis and etiology of this disorder but also to that of dystonia and parkinsonism in general.